/Engine/Source/Editor/GraphEditor/Public/SNodePanel.h
Paint the marquee selection rectangle.
void PaintMarquee ( const [FGeometry](API\Runtime\SlateCore\Layout\FGeometry) & AllottedGeometry, const [FSlateRect](API\Runtime\SlateCore\Layout\FSlateRect) & MyCullingRect, [FSlateWindowElementList](API\Runtime\SlateCore\Rendering\FSlateWindowElementList) & OutDrawElements, int32 DrawLayerId ) const